diff --git a/crates/mcp/src/tools.rs b/crates/mcp/src/tools.rs
index 86cf9ff0..2d1c2158 100644
--- a/crates/mcp/src/tools.rs
+++ b/crates/mcp/src/tools.rs
@@ -308,7 +308,7 @@ pub fn helper_tools(has_ui: bool) -> Vec<Value> {
             tool(
                 "clipboard",
                 "Cut, copy or paste",
-                "Cut, copy or paste in the focused text field, as ⌘X / ⌘C / ⌘V do. `paste` pastes `text`, or what the system clipboard holds without it. inspect_ui → `copied` is the text the app last copied.",
+                "Cut, copy or paste in the focused text field (click one first), as ⌘X / ⌘C / ⌘V do; cut and copy write the system clipboard. `paste` pastes `text`, or what the system clipboard holds without it. inspect_ui → `copied` is the text the app last copied.",
                 json!({"action": {"type": "string", "enum": ["cut", "copy", "paste"]}, "text": {"type": "string"}}),
                 &["action"],
             ),
diff --git a/crates/ui-egui/src/control.rs b/crates/ui-egui/src/control.rs
index 592a58de..9cee4435 100644
--- a/crates/ui-egui/src/control.rs
+++ b/crates/ui-egui/src/control.rs
@@ -278,6 +278,11 @@ pub fn handle(app: &mut LightcraftApp, ctx: &egui::Context, req: &ControlRequest
         // what the system does for ⌘X / ⌘C / ⌘V in a text field: paste `text`, or (without it)
         // what the system clipboard holds
         "ui.clipboard" => {
+            // outside a text field ⌘C / ⌘V are the app's shortcuts (and the macOS menu bar's):
+            // agents run those as commands (`develop.copy`, `develop.paste`)
+            if !ctx.text_edit_focused() {
+                return err("ui.clipboard: no text field has the focus (click one first)");
+            }
             match s("action") {
                 Some("cut") => app.synthetic.push(egui::Event::Cut),
                 Some("copy") => app.synthetic.push(egui::Event::Copy),
diff --git a/crates/ui-egui/src/headless.rs b/crates/ui-egui/src/headless.rs
index e77c45b0..bdee47ab 100644
--- a/crates/ui-egui/src/headless.rs
+++ b/crates/ui-egui/src/headless.rs
@@ -662,6 +662,23 @@ mod tests {
         assert_eq!(r["ok"], false, "an unknown action is refused: {r}");
     }
 
+    /// `ui.clipboard` acts in a text field: with none focused it is refused, rather than doing
+    /// what ⌘V does there on one platform (paste edit settings) and nothing on another.
+    #[test]
+    fn the_clipboard_method_needs_a_text_field() {
+        let mut h = demo([1200.0, 760.0]);
+        let t = Duration::from_secs(10);
+        h.settle(SETTLE);
+        let undo = h.app.session.undo.len();
+        for action in ["copy", "paste"] {
+            let r = h.request("ui.clipboard", json!({"action": action, "text": "travel"}), t);
+            assert_eq!(r["ok"], false, "{action}: {r}");
+            assert!(r["error"].as_str().is_some_and(|e| e.contains("text field")), "{r}");
+        }
+        h.settle(SETTLE);
+        assert_eq!(h.app.session.undo.len(), undo, "nothing was pasted");
+    }
+
     /// `ui.clickWidget` right-clicks with `button: "right"`, as `ui.click` does (MCP `click`
     /// passes it on with a widget): a filmstrip photo's context menu opens.
     #[test]
diff --git a/docs/control-protocol.md b/docs/control-protocol.md
index c0317b58..6f50b3f7 100644
--- a/docs/control-protocol.md
+++ b/docs/control-protocol.md
@@ -37,7 +37,7 @@ mode ([mcp.md](mcp.md)) is a thin layer over this channel. Implementation:
 | `ui.pointer` | `{events: [{kind: down\|drag\|up, x, y}], alt?, shift?, cmd?}` | Gesture in normalized image coordinates (Detail view) |
 | `ui.key` | `{key, cmd?, shift?, alt?, ctrl?}` | Key press |
 | `ui.text` | `{text}` | Text input |
-| `ui.clipboard` | `{action: cut\|copy\|paste, text?}` | Cut, copy or paste in the focused text field, as the system does for ⌘X / ⌘C / ⌘V; `paste` pastes `text`, or the system clipboard without it. `ui.inspect` → `copied` is the text the UI last put on the clipboard |
+| `ui.clipboard` | `{action: cut\|copy\|paste, text?}` | Cut, copy or paste in the focused text field, as the system does for ⌘X / ⌘C / ⌘V; `paste` pastes `text`, or the system clipboard without it. Refused when no text field has the focus (outside one, ⌘C / ⌘V are the commands `develop.copy` / `develop.paste`). In the desktop app cut and copy write the system clipboard. `ui.inspect` → `copied` is the text the UI last put on the clipboard |
 | `ui.scroll` | `{dx, dy, cmd?, ctrl?, shift?, alt?}` | Wheel / two-finger scroll at the current pointer; pans over the image, modifier-scroll zooms |
 | `ui.zoom` | `{factor}` | Pinch zoom at the current pointer (positive scale multiplier; 1 = unchanged). Position it first with `ui.move` or `ui.hoverWidget` |
 | `ui.set` | partial UI state, e.g. `{"view": "detail"}` | Resulting UI state |
diff --git a/docs/mcp.md b/docs/mcp.md
index 2dfe59c1..a6b69a26 100644
--- a/docs/mcp.md
+++ b/docs/mcp.md
@@ -134,7 +134,7 @@ Tools taking `id` make that photo active first; without it they act on the activ
 | `set_ui {state}` | Merge UI state, e.g. `{"view": "detail"}` |
 | `list_widgets {filter?}` / `click {widget \| x,y, count?}` | Widgets by automation id; real egui clicks |
 | `press_key {key, cmd?, shift?, alt?}` / `type_text {text}` | Keyboard input (shortcuts) |
-| `clipboard {action, text?}` | Cut, copy or paste in the focused text field (⌘X / ⌘C / ⌘V); `inspect_ui` → `copied` is what was copied |
+| `clipboard {action, text?}` | Cut, copy or paste in the focused text field (⌘X / ⌘C / ⌘V; refused when none has the focus; cut and copy write the system clipboard); `inspect_ui` → `copied` is what was copied |
 | `pointer_gesture {events}` | Gestures in normalized image coordinates (brush strokes, gradients, crop handles) |
 
 In headless mode these return a tool error explaining how to start the app.